Reland "Remove GICE (gone forever!) and PORTALLOCATOR_ENABLE_SHARED_UFRAG (enabled forever)." becauese remoting code is using dead constants and breaks the FYI bots."

This reverts commit 475243a134be003aab30bb17294ca6c664d0ef81.

R=guoweis@webrtc.org

Review URL: https://codereview.webrtc.org/1291363005 .

Cr-Commit-Position: refs/heads/master@{#9738}
47 files changed